Prevalence of human papillomavirus types in cervical cancerous and precancerous lesions of Ecuadorian women

Abstract

Human Papillomavirus (HPV) is the most common sexually transmitted infection worldwide and it is responsible for most cases of uterine cancer. In Ecuador there is limited information about HPV types (and variants) in cancerous lesions; however, identifying the type-specific HPV prevalence in cervical lesions of women living in Ecuador is important to better predict the impact of HPV prophylactic vaccination in this country. We studied the prevalence of HPV types in cervical cancerous or precancerous lesions from 164 Ecuadorian women and found that 86.0% were HPV positive. The most common types were HPV16 (41.8%) and HPV58 (30.5%). Interestingly, HPV18 was detected only in 2.8% of the HPV-positive samples. Fifteen DNA sequences (genes E6 and L1) from 16 samples positive for HPV16 belonged to the European lineage, considered one of the least carcinogenic lineages, and 1 (6.25%) to the Asian-American lineage. Similar analysis in 12 HPV58 positive samples showed that 10 (83.3%) sequences grouped in sublineage A2, which belongs to the oldest HPV58 lineage, 1 belonged to A3 and 1 to lineage C. This study suggests that the currently used HPV vaccines (bivalent and tetravalent) may have lower effectiveness in Ecuador than in other geographic locations where HPV18 is more prevalent.

Prevalence of High-Risk Genotypes of Human Papillomavirus: Women Diagnosed with Premalignant and Malignant Pap Smear Tests in Southern Ecuador

“…Studies in Ecuador found genotype 16 as the most common [32, 33, 35, 40], along with results of this investigation. The 18 genotype was not reported as the second most frequent, suggesting that genotypic variability by geographic region and sociodemographic factors had an effect, such that more research is necessary.…”

“…The prevalence of high-risk HPV in cytological samples was 64.5%. In Quito, Ecuador, they reported other studies in cytological and/or histologically altered, in which the reported prevalence of HPV was found to be low risk at 67.7% and 86% [32, 33]. In the city of Cuenca, in a study of 500 women from the general population, the prevalence of 25.6% of HPV for both high and low risk [34] was similar to that reported in Santa Elena.…”

A novel arylbenzofuran induces cervical cancer cell apoptosis and G1/S arrest through ERK-mediated Cdk2/cyclin-A signaling pathway

“…High risk-HPV (HR-HPV) infection is considered to be a major risk factor of cervical cancer development and precancerous lesions [4–6], such as HPV16, 18, 31, and 33 promote in cervical cancer pathogenesis [7–9]. Among all these types of HPV, types 16 and 18 are the most dangerous factors which are approximately 70 percent in cervical cancer [10, 11], but vaccine against HPV could not effectively prevented pre-existing HPV infections and progression of HPV-associated lesions. In current, the therapeutic regimens of cervical cancer include surgical removal, radiotherapy and chemotherapy.…”

Atividade mucosotrópica do Papilomavírus Humano (HPV) no processo carcinogênico em diferentes sítios de infecção.

“…Os resultados mostram que o HPV-16 foi o tipo viral mais prevalente na mucosa cervical, mucosa oral e sangue periférico, o que já era esperado pela alta prevalência desse tipo viral, no Brasil e no mundo (ARIAS et al, 2010;BRUNO et al, 2014;ESMAEILI et al, 2008;JAREBIPOUR et al, 2011;MEJÍA et al, 2016). O segundo tipo mais frequente foi o HPV-33, seguido do HPV-18 e o menos frequente foi o HPV-31.…”

“…Dessa forma, não seria sugestivo uma possível latência viral, de maneira que essas pacientes já apresentam lesões na cérvice causadas pelo HPV (CHEN et al, 2014;DERCHAIN et al, 2005;LAWSON et al, 2016;MEJÍA et al, 2016). Nas lesões intraepiteliais de baixo grau a falta da integração é geralmente observada, enquanto que a integração é um importante fator para a progressão das lesões intraepiteliais para câncer invasivo e pode ser um marcador potencial para avaliação de risco de progressão das lesões intraepitelais.…”